A saw set
is a device used in the sharpening
of hand saws
. Once the teeth have been jointed and filed, the saw set is used to adjust the set
of each tooth.
In the past, many tradesmen and craftsmen would sharpen their own saws and a saw set would be a common tool to find in the toolbox. In more recent times, modern hand saws are considered disposable and are rarely if ever sharpened.
The word 'set' when used in regard to saws has several meanings. It is simultaneously the amount of bend of a saw tooth, the operation of bending a tooth or teeth and the tool used to produce the bend. Most commonly, the 'set' is the amount by which the tooth protrudes from the side of the blade. Most saws have some amount of set, which creates a slot kerf
that is wider than the blade and thereby prevents binding as the non-cutting part of the saw blade enters the cut. This makes it easier to make the cut and allows more control over direction. The amount of set is a compromise between the size of the kerf and the ease of cutting. Carpenter's hand saws have alternate teeth set in opposite directions so that an equal number of teeth protrude from each side of the blade. Crosscut and some circular saws have different arrangements because not all of their teeth cut.
Set must be identical and small. If set varies, the cut is wavy on each stroke. If too large, the cut wanders from a desired line; the saw is difficult or impossible to control. Too much wood is removed, tiring the worker. If too small, the saw binds or is very difficult to use.
Saws with insert teeth use teeth made wider than the blade to get the same result; a saw that cuts easily and smoothly by making the kerf wider than the blade. Another technique, swaging, deforms the tooth so it is wider at its tip than its base.
Forms of a saw set
From 1810 to 1925 almost 900 different saw sets were patented. Todd Friberg "Patented American Saw Sets" Osage Press. The earliest ones were a slot in an iron bar (wrest). A common form of a saw set is a device which resembles a pair of pliers
. In use, the head of the saw set is located on the blade adjacent to the tooth to which set is to be applied. The handles of the saw set are squeezed together and a hardened steel plunger forces the tooth in the desired direction.
The later saw sets are generally of a 'pistol grip' configuration. With one movement of the handle, a dual action mechanism first locks the saw set around the blade then the plunger bends the tooth as above.
There are even saw sets that set more than one tooth at a time. Another popular design used a captive hammer, often spring loaded.
Most saw sets have an adjustment screw which allows the amount of set to be determined by the location of a hardened steel plate (anvil) on the opposite side of the device to the plunger. The plunger pushes the tooth against this plate.